1 files changed, 46 insertions, 22 deletions

diff --git a/drivers/staging/most/aim-cdev/cdev.c b/drivers/staging/most/aim-cdev/cdev.c
index 0a13d8d0fa39..dc3fb25b52aa 100644
--- a/drivers/staging/most/aim-cdev/cdev.c
+++ b/drivers/staging/most/aim-cdev/cdev.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/poll.h>
 #include <linux/kfifo.h>
 #include <linux/uaccess.h>
 #include <linux/idr.h>
@@ -27,6 +28,7 @@ static dev_t aim_devno;
 static struct class *aim_class;
 static struct ida minor_id;
 static unsigned int major;
+static struct most_aim cdev_aim;
 
 struct aim_channel {
 	wait_queue_head_t wq;
@@ -44,11 +46,11 @@ struct aim_channel {
 	atomic_t access_ref;
 	struct list_head list;
 };
+
 #define to_channel(d) container_of(d, struct aim_channel, cdev)
 static struct list_head channel_list;
 static spinlock_t ch_list_lock;
 
-
 static struct aim_channel *get_channel(struct most_interface *iface, int id)
 {
 	struct aim_channel *channel, *tmp;
@@ -85,8 +87,8 @@ static int aim_open(struct inode *inode, struct file *filp)
 	filp->private_data = channel;
 
 	if (((channel->cfg->direction == MOST_CH_RX) &&
-	     ((filp->f_flags & O_ACCMODE) != O_RDONLY))
-	    || ((channel->cfg->direction == MOST_CH_TX) &&
+	     ((filp->f_flags & O_ACCMODE) != O_RDONLY)) ||
+	     ((channel->cfg->direction == MOST_CH_TX) &&
 		((filp->f_flags & O_ACCMODE) != O_WRONLY))) {
 		pr_info("WARN: Access flags mismatch\n");
 		return -EACCES;
@@ -97,7 +99,8 @@ static int aim_open(struct inode *inode, struct file *filp)
 		return -EBUSY;
 	}
 
-	ret = most_start_channel(channel->iface, channel->channel_id);
+	ret = most_start_channel(channel->iface, channel->channel_id,
+				 &cdev_aim);
 	if (ret)
 		atomic_dec(&channel->access_ref);
 	return ret;
@@ -131,11 +134,11 @@ static int aim_close(struct inode *inode, struct file *filp)
 	}
 	mutex_unlock(&channel->io_mutex);
 
-	while (0 != kfifo_out((struct kfifo *)&channel->fifo, &mbo, 1))
+	while (kfifo_out((struct kfifo *)&channel->fifo, &mbo, 1))
 		most_put_mbo(mbo);
-	if (channel->keep_mbo == true)
+	if (channel->keep_mbo)
 		most_put_mbo(channel->stacked_mbo);
-	ret = most_stop_channel(channel->iface, channel->channel_id);
+	ret = most_stop_channel(channel->iface, channel->channel_id, &cdev_aim);
 	atomic_dec(&channel->access_ref);
 	wake_up_interruptible(&channel->wq);
 	return ret;
@@ -165,16 +168,17 @@ static ssize_t aim_write(struct file *filp, const char __user *buf,
 	}
 	mutex_unlock(&channel->io_mutex);
 
-	mbo = most_get_mbo(channel->iface, channel->channel_id);
+	mbo = most_get_mbo(channel->iface, channel->channel_id, &cdev_aim);
 
-	if (!mbo && channel->dev) {
+	if (!mbo) {
 		if ((filp->f_flags & O_NONBLOCK))
 			return -EAGAIN;
 		if (wait_event_interruptible(
 			    channel->wq,
 			    (mbo = most_get_mbo(channel->iface,
-						channel->channel_id)) ||
-			    (channel->dev == NULL)))
+						channel->channel_id,
+						&cdev_aim)) ||
+			    (!channel->dev)))
 			return -ERESTARTSYS;
 	}
 
@@ -204,8 +208,7 @@ static ssize_t aim_write(struct file *filp, const char __user *buf,
 	}
 	return actual_len - retval;
 error:
-	if (mbo)
-		most_put_mbo(mbo);
+	most_put_mbo(mbo);
 	return err;
 }
 
@@ -224,18 +227,17 @@ aim_read(struct file *filp, char __user *buf, size_t count, loff_t *offset)
 	struct mbo *mbo;
 	struct aim_channel *channel = filp->private_data;
 
-	if (channel->keep_mbo == true) {
+	if (channel->keep_mbo) {
 		mbo = channel->stacked_mbo;
 		channel->keep_mbo = false;
 		goto start_copy;
 	}
-	while ((0 == kfifo_out(&channel->fifo, &mbo, 1))
-	       && (channel->dev != NULL)) {
+	while ((!kfifo_out(&channel->fifo, &mbo, 1)) && (channel->dev)) {
 		if (filp->f_flags & O_NONBLOCK)
 			return -EAGAIN;
 		if (wait_event_interruptible(channel->wq,
 					     (!kfifo_is_empty(&channel->fifo) ||
-					      (channel->dev == NULL))))
+					      (!channel->dev))))
 			return -ERESTARTSYS;
 	}
 
@@ -259,7 +261,7 @@ start_copy:
 
 	retval = not_copied ? proc_len - not_copied : proc_len;
 
-	if (channel->keep_mbo == true) {
+	if (channel->keep_mbo) {
 		channel->mbo_offs = retval;
 		channel->stacked_mbo = mbo;
 	} else {
@@ -270,6 +272,28 @@ start_copy:
 	return retval;
 }
 
+static inline bool __must_check IS_ERR_OR_FALSE(int x)
+{
+	return x <= 0;
+}
+
+static unsigned int aim_poll(struct file *filp, poll_table *wait)
+{
+	struct aim_channel *c = filp->private_data;
+	unsigned int mask = 0;
+
+	poll_wait(filp, &c->wq, wait);
+
+	if (c->cfg->direction == MOST_CH_RX) {
+		if (!kfifo_is_empty(&c->fifo))
+			mask |= POLLIN | POLLRDNORM;
+	} else {
+		if (!IS_ERR_OR_FALSE(channel_has_mbo(c->iface, c->channel_id)))
+			mask |= POLLOUT | POLLWRNORM;
+	}
+	return mask;
+}
+
 /**
  * Initialization of struct file_operations
  */
@@ -279,6 +303,7 @@ static const struct file_operations channel_fops = {
 	.write = aim_write,
 	.open = aim_open,
 	.release = aim_close,
+	.poll = aim_poll,
 };
 
 /**
@@ -300,7 +325,7 @@ static int aim_disconnect_channel(struct most_interface *iface, int channel_id)
 	}
 
 	channel = get_channel(iface, channel_id);
-	if (channel == NULL)
+	if (!channel)
 		return -ENXIO;
 
 	mutex_lock(&channel->io_mutex);
@@ -337,7 +362,7 @@ static int aim_rx_completion(struct mbo *mbo)
 		return -EINVAL;
 
 	channel = get_channel(mbo->ifp, mbo->hdm_channel_id);
-	if (channel == NULL)
+	if (!channel)
 		return -ENXIO;
 
 	kfifo_in(&channel->fifo, &mbo, 1);
@@ -370,7 +395,7 @@ static int aim_tx_completion(struct most_interface *iface, int channel_id)
 	}
 
 	channel = get_channel(iface, channel_id);
-	if (channel == NULL)
+	if (!channel)
 		return -ENXIO;
 	wake_up_interruptible(&channel->wq);
 	return 0;
@@ -413,7 +438,6 @@ static int aim_probe(struct most_interface *iface, int channel_id,
 
 	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 	if (!channel) {
-		pr_info("failed to alloc channel object\n");
 		retval = -ENOMEM;
 		goto error_alloc_channel;
 	}